Abstract
The effect of unitary noise on the discrete one-dimensional quantum walk is studied using computer simulations. For the noiseless quantum walk, starting at the origin at time the position distribution at time t is very different from the Gaussian distribution obtained for the classical random walk. Furthermore, its standard deviation, scales as unlike the classical random walk for which It is shown that when the quantum walk is exposed to unitary noise, it exhibits a crossover from quantum behavior for short times to classical-like behavior for long times. The crossover time is found to be where is the standard deviation of the noise.
- Received 10 February 2003
DOI:https://doi.org/10.1103/PhysRevA.68.062315
©2003 American Physical Society